this.function = checkNotNull(function);
    this.ordering = checkNotNull(ordering);
  }

  @Override
  public int compare(@ParametricNullness F left, @ParametricNullness F right) {
    return ordering.compare(function.apply(left), function.apply(right));
  }

  @Override
  public boolean equals(@CheckForNull Object object) {
    if (object == this) {
      return true;
    }

    this.comparators =
        Iterables.toArray(comparators, (Comparator<? super T>[]) new Comparator<?>[0]);
  }

  @Override
  public int compare(@ParametricNullness T left, @ParametricNullness T right) {
    for (int i = 0; i < comparators.length; i++) {
      int result = comparators[i].compare(left, right);
      if (result != 0) {
        return result;
      }
    }
    return 0;
  }

  @Override

    this.comparators =
        Iterables.toArray(comparators, (Comparator<? super T>[]) new Comparator<?>[0]);
  }

  @Override
  public int compare(@ParametricNullness T left, @ParametricNullness T right) {
    for (int i = 0; i < comparators.length; i++) {
      int result = comparators[i].compare(left, right);
      if (result != 0) {
        return result;
      }
    }
    return 0;
  }

  @Override

 *   if (value < 0) {
 *     throw new IllegalArgumentException("input is negative: " + value);
 *   }
 *   // calculate square root
 * }
 * }</pre>
 *
 * <p>to be replaced with the more compact
 *
 * <pre>{@code
 * public static double sqrt(double value) {
 *   checkArgument(value >= 0, "input is negative: %s", value);
 *   // calculate square root
 * }
 * }</pre>
 *

          () -> InetAddresses.getCompatIPv4Address((Inet6Address) ip));
    }

    ImmutableSet<String> validCompatAddresses = ImmutableSet.of("::1.2.3.4", "::102:304");
    String compatStr = "1.2.3.4";
    InetAddress compat = InetAddresses.forString(compatStr);

    for (String validCompatAddress : validCompatAddresses) {
      InetAddress ip = InetAddresses.forString(validCompatAddress);

    // Pretend the comparator can compare anything. If it turns out it can't
    // compare a and b, we should get a CCE or NPE on the subsequent line. Only methods
    // that are spec'd to throw CCE and NPE should call this.
    @SuppressWarnings({"unchecked", "nullness"})
    Comparator<@Nullable Object> unsafeComparator = (Comparator<@Nullable Object>) comparator;
    return unsafeComparator.compare(a, b);
  }

                      @Override
                      public int compare(Entry<String, String> left, Entry<String, String> right) {
                        return ComparisonChain.start()
                            .compare(left.getKey(), right.getKey(), Ordering.natural().nullsFirst())
                            .compare(
                                left.getValue(), right.getValue(), Ordering.natural().nullsFirst())

       *
       * 1. On Android, querying a WeakReference blocks if the GC is doing an otherwise-concurrent
       * pass.
       *
       * 2. We would probably choose to compare exceptions using == instead of equals() (for
       * consistency with how weak references are cleared). That's a behavior change -- arguably the
       * removal of a feature.
       *

        }
      };

  private static final Ordering<Invokable<?, ?>> BY_NUMBER_OF_PARAMETERS =
      new Ordering<Invokable<?, ?>>() {
        @Override
        public int compare(Invokable<?, ?> left, Invokable<?, ?> right) {
          return Ints.compare(left.getParameters().size(), right.getParameters().size());
        }
      };

   */
  public static boolean isUriInetAddress(String ipString) {
    return forUriStringNoThrow(ipString) != null;
  }

  /**
   * Evaluates whether the argument is an IPv6 "compat" address.
   *
   * <p>An "IPv4 compatible", or "compat", address is one with 96 leading bits of zero, with the
   * remaining 32 bits interpreted as an IPv4 address. These are conventionally represented in